Yes, I didn't pay my attention on my h2reg.ini. It just registers my help collection. I use this script with the previous version of my help project which explicitly puts namespace definitions in <mshelp:link /> nodes.

I have this same problem, but I'm new to building help, and didn't understand the answer. I looked on my machine, and I have a
Help2x_H2Reg.ini in C:\Program Files\EWSoftware\Sandcastle Help File Builder\Templates, but no
h2reg.ini anywhere else. Could someone please give more details on how to fix this?